Estimation of Wheelchair Cushion Seating Comfort based on Subjective Evaluations and Body Weight Distribution

Abstract

This fundamental research investigated use of a novel method of indexing cushion material seating comfort in the development of new wheelchair cushion materials. Subjective experiments and body pressure distribution measurements were conducted using 14 specimens of differing materials and specifications. Added in the specimens were newly developed cushions consisting of a multi-layered composite material and a cushion with a bottom plate attached. Subjective experiments employed the SD method, with 20 healthy male and female subjects evaluating 12 material criteria. Body pressure distribution was measured in ranges of 20 mm Hg, and total area, maximum pressure, and average pressure were measured for each cushion. Measurements of body pressure distribution, previous based on a single approach, were derived by incorporating the area of the cushions for each pressure range. The results revealed body pressure distribution to be highly correlated to five psychological evaluation categories. From the results of the subjective experiments and body pressure distribution measurements, multiple regression analysis yielded a multiple regression formula to estimate seating comfort evaluation, with total area, maximum pressure, average pressure, and the area of each zone as explanatory variables.